Terahertz (THz) waves have exhibited promising prospects in 6G/7G communications, sensing, nondestructive detection, material modulation, and biomedical applications. With the development of high-power THz sources, more and more nonlinear optical effects at THz frequency and THz-induced nonlinear optical phenomena are investigated. These studies not only show a clear physics picture of electrons, ions, and molecules but also provide many novel applications in sensing, imaging, communications, and aerospace. Here, we review recent developments in THz nonlinear physics and THz-induced nonlinear optical phenomena. This review provides an overview and illustrates examples of how to achieve strong THz nonlinear phenomena and how to use THz waves to achieve nonlinear material modulation.

中文翻译：

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太赫兹频率下的非线性光学物理


太赫兹（THz）波在6G/7G通信、传感、无损检测、材料调制和生物医学应用中展现出广阔的前景。随着高功率太赫兹源的发展，越来越多的太赫兹频率下的非线性光学效应和太赫兹引起的非线性光学现象被研究。这些研究不仅展示了电子、离子和分子的清晰物理图景，而且在传感、成像、通信和航空航天领域提供了许多新颖的应用。在这里，我们回顾了太赫兹非线性物理和太赫兹引起的非线性光学现象的最新进展。本综述提供了如何实现强太赫兹非线性现象以及如何使用太赫兹波实现非线性材料调制的概述并举例说明。